Industrial Wireless Technology: Communication and Programming

There was a time when wireless technology was virtually entirely impractical within industrial environments. Cybersecurity issues, often stemming from a fundamental lack of experience from many production floor technicians, as well as instability in signals caused by equipment could cause unexpected motion or downtime in production.

 

Modern Industrial Wireless Communication

Today, the industry is changing. There are wireless sensors, routers, and even new wireless protocols appearing across the market, designed specifically for industrial automation equipment. Many in the industry are realizing the benefits of wireless communication, leading to enough adoption to justify advancing the technology enough to reduce many of the risks of past years.

 

Figure 1. Example of a wireless LAN access point. Image used courtesy of Siemens

 

Wireless Modules for Mobile Robotics

Automated guided vehicles, AGVs, are becoming very popular in automated warehouses and assembly factories. An AGV is used to transport material or products from a storage shelf to a location where the material is required or where the product will be packaged for shipping.

Most AGVs communicate with a central control system or SCADA system to submit their current location and payload information. The control system will reply to the AGV with a destination and instructions to deliver the payload or identify the closest charging station when the battery supply is reduced.

This communication needs to be done wirelessly so that the vehicles have the freedom to travel through the factory floor without a bulky (and often dangerous) tether. Industrial wireless access points are used to create a wireless cloud network that all the AGVs can connect to, such as the Siemens Scalance series. This access point has all the features of Siemens wired routers but with the benefit of wireless technology.

 

Figure 2. Mobile autonomous robot interacting with industrial robots. Image used courtesy of Wikipedia

 

Wireless Sensors

Not only are robotics taking the plunge into wireless technology, but so are sensors. With wireless IO-Link technology, simple proximity sensors, analog sensors, or even actuators can be controlled wirelessly, opening many doors for unique solutions to engineering problems.

To accommodate wireless sensors, many innovative solutions are being explored. Some sensors, when given an appropriate power supply, transmit a discrete or analog signal on a reliable RF network. The signal is received by a controller module or by an adapter that converts the wireless signal into a standard fieldbus, much like a distributed I/O bus.

Some wireless devices plug into existing sensors, receiving the standard discrete or analog signal and converting it to a wireless RF output. This relaying adapter can also turn IO-Link devices into IO-Link wireless signals, as exemplified by these IO-Link hubs and converters from Balluff which can convert either multiple or a single IO-Link device into a wireless node.

 

Figure 3. Example of IO-Link Wireless hubs and converters. Image used courtesy of Balluff

 

Wireless Tooling Changeover Example

Recently, Rotzinger, an automated packaging equipment manufacturer out of Switzerland and Germany with an office in Pennsylvania, has leveraged wireless IO-Link technology to solve a problem that plagues many equipment builders, the dreaded changeover. Changing over tooling to accommodate multiple part types results in a loss of production.

Manufacturers always want to run as many different types of products as they can on one machine, so to accommodate that desire, equipment builders will incorporate tooling that can be changed quickly to facilitate running different part types.

Rotzinger’s solution utilized wireless IO-Link actuators so that production didn’t need to stop in order to run multiple parts. They accomplished this by putting grippers directly on a servo conveyor. This allowed one or two products to be packaged at a time, all without changing tooling or stopping the equipment.

 

Figure 4. Wireless sensors on robot grippers can facilitate faster tool changes and increased production. Image courtesy of FANUC

 

Mobile Manufacturing Equipment

Smaller manufacturing companies are starting to take advantage of automation to stay competitive, but the equipment they invest in needs to be flexible and mobile.

Mobile CNC-tending robotics is a great tool for smaller machine shops to stay ahead of their competitors. Some of the mobile robotic tending systems have pre-integrated wireless technology reporting back to a centralized SCADA system. This system can display machine analytics, cycle time reports, and even location.

A major obstacle with machine tending systems is the type of CNC machine; most companies have multiple kinds of machines, possibly all with different control systems. By adding wireless technology to both the CNC machine and the robot system, it won’t matter if the tending system is a FANUC, SINUMERIK, Doosan, or anything else, the communication will always be the same.

 

Figure 5. SCADA systems rely heavily on communication. Image used courtesy of Wikipedia

 

Wireless Programming

Tripping hazards, broken laptops, and destroyed Ethernet cables and ports are some of the problems that maintenance and controls engineers face on a daily bases. These issues could be readily solved if we did not need to plug into equipment.

Connecting to equipment wirelessly is very convenient, but realistically, it can present safety issues. Once connected to an industrial private network, equipment can move unexpectedly and if there isn’t somebody with a laptop nearby, operators or people in the area might be startled or injured. With proper protocols and operating procedures, creating a private wireless network can save on safety devices and reduce troubleshooting time.

If using a wireless network for programming, you need to ensure the network is secure and capable of supporting high-speed traffic. A slow or intermittent connection is not only frustrating for the programmer but also could result in the loss of code changes.

 

Communication in SCADA Systems

A SCADA system reads sensor data from within the equipment and displays it in a centralized location. Typically, the SCADA system will read sensor data through a PLC or RTU, by setting up a wireless network between the SCADA system and the control system, you reduce the need for running additional network cables, and your SCADA system can be mobile. Some SCADA systems communicate directly with the sensors, so running cables to multiple sensors around a factory or plant could be costly.

With the use of wireless access points, the communication between sensors and SCADA controller is quite simple and can span large distances with very limited latencies.

 

Wireless Is Knocking At The Door

With the above examples, you can see that there are many different applications for wireless technology. While some might be convenient, many could indeed be considered an increase in safety risks.

As the technology becomes more affordable and security features are increased, wireless options are likely to become more attractive for machine or plant industrial network solutions.